Real Estate Investments, Net (Summary of Intangible Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Intangible assets:
Gross Carrying Amount	$ 288,372	$ 276,015
Accumulated Amortization	195,291	184,664
Net Carrying Amount	93,081	91,351
Intangible liabilities:
Gross Carrying Amount	23,472	22,109
Accumulated Amortization	12,529	11,306
Net Carrying Amount	10,943	10,803
In-place leases and other intangible assets
Intangible assets:
Gross Carrying Amount	264,741	241,097
Accumulated Amortization	183,073	172,648
Net Carrying Amount	81,668	68,449
Market lease assets
Intangible assets:
Gross Carrying Amount	14,164	14,116
Accumulated Amortization	11,212	10,845
Net Carrying Amount	2,952	3,271
Other intangible assets
Intangible assets:
Gross Carrying Amount	9,467	20,802
Accumulated Amortization	1,006	1,171
Net Carrying Amount	$ 8,461	$ 19,631